APS Record Shattered: Customers’ Energy Use Sets New Peak Twice in Two Days

Diverse power supply and resilient electric grid keep AC units running


PHOENIX – After 17 straight days of temperatures at or above 110 degrees and air conditioners cranking to keep Arizonans cool, Arizona Public Service (APS) customers demand reached 8,191 megawatts (MW) on Saturday, July 15. That set the peak for the most electricity used at once in APS history.


“APS is ranked as one of the most reliable electric utilities in the country, and during this heatwave when customers need us the most, we deliver with dependable, around-the-clock electricity,” said Ted Geisler, APS President. “I'm very proud of the entire APS team – from the planners who start strategizing years in advance to our operators, customer care team and field crews who showed up during extreme conditions for Arizonans and met their record-breaking demand for power.”


APS customers first made history Friday, July 14, shattering the previous energy demand record, set in 2020. APS Vice President of Resource Management Justin Joiner said multiple factors contribute to increases in electricity use, including temperatures, humidity and more people and businesses moving to Arizona.


“On days when the temperature is sweltering, we take an all-of-the-above approach. We’re using all the tools in our toolbox— from solar power to natural gas— to make sure customers can count on us for electricity every second of the day,” said Joiner. “Our power plants are running smoothly, and the energy supply is robust. That’s what proactive, year-round planning looks like.”


Here’s a look at the numbers:

  • APS’s prior all-time record was 7,660 MW set on July 30, 2020.
  • On Friday, July 14, customers surpassed the record, using 7,798 MW of energy.
  • Friday’s record was broken Saturday, July 15, with 8,191 MW of energy consumed at once, resulting in the highest amount of combined energy use in APS history.
  • Sunday, July 16, customers’ peak energy demand was 7,962 MW, well above the peak set in 2020, and above Friday’s peak, but not enough to break the new all-time peak set Saturday.


How APS Maintains Power Supply


APS plans years in advance to continue serving customers with reliable and affordable energy. Resource planners secure a diverse energy mix to meet demand, like solar and wind power, battery energy storage and the APS-operated Palo Verde Generating Station, the largest nuclear power plant in the U.S. and the country’s largest producer of clean energy. When temperatures cause demand to increase, APS’s strength and resilience comes from utilizing flexible resources like natural gas to keep homes and businesses cool over long stretches of extreme heat temperatures.


Each year APS invests more than $1.5 billion to maintain and upgrade the grid, replacing aging electrical equipment and installing new technology. APS crews maintain more than 38,000 miles of power lines and use advanced smart technology as well as drones and robots to detect potential issues with equipment before they cause problems.


Customer Tips as Summer Heat Continues


APS customers typically use the most power between the hours of 4 p.m. and 7 p.m. While APS is well prepared to deliver the energy customers need as summer continues, conserving power during peak hours of the day can help customers reduce energy bills while supporting grid reliability.


  • For those on APS time-of-use plans, (Time-of-Use 4pm-7pm Weekdays and Time-of-Use 4pm-7pm Weekdays with Demand Charge), try pre-cooling your home. Set your thermostat a few degrees lower than normal before 4 p.m. and then set it a few degrees higher than normal during the on-peak period of 4 p.m. to 7 p.m.

  • Service your air conditioner annually to ensure it runs efficiently and change air filters monthly.
  • Think 1, 2, 3 and turn your thermostat up a few degrees. For every one degree you raise your thermostat, you can save 2-3% on energy cooling costs. (When on vacation, turn it up more.)
  • Use a smart thermostat to “set it and forget it.” We offer special rebates and discounts on the APS Marketplace.
  • Close curtains and blinds during the day.
  • Use fans to feel up to 5 degrees cooler. Set ceiling fans to run counterclockwise and remember fans cool people, not rooms, so turn off when you leave.
  • Earn bill credits. Join APS Cool Rewards (residential) or APS Peak Solutions (business) – programs that reward customers for conserving energy during times when usage is highest.
  • Switch to LED lighting. LED bulbs emit 90 percent less heat than traditional incandescent bulbs.
  • Limit oven use; when possible, use the microwave, toaster oven or outdoor grill instead.
  • Stay informed. Use the APS mobile app and aps.com to monitor and manage your energy use and to learn more energy-saving tips customized to your service plan.


Visit aps.com/tips for more ways to save and learn more about assistance programs and heat relief resources at aps.com/assistance.

backyard ac unit

APS serves more than 1.3 million homes and businesses in 11 of Arizona’s 15 counties, and is a leader in delivering affordable, clean and reliable energy in the Southwest. The company is committed to serving customers with 100% clean power by 2050. As owner and operator of Palo Verde Generating Station, the nation’s largest producer of carbon-free electricity, and with one of the country’s most substantial renewable energy portfolios, APS’s current energy mix is 51% clean. With headquarters in Phoenix, APS is the principal subsidiary of Pinnacle West Capital Corp. (NYSE: PNW).

Related stories

Looking Ahead: New APS Plan Addresses Growing Customer Energy Needs
Simple Changes at Home Can Reduce Energy Costs
Clean Energy Week 2023: New APS Solar Power Plant in Service
View up to date news, articles and stories related to APS in the community.
Copyright © 2024 APS.  All rights reserved.
Current server address is